Colleen Deacon, a New York-based aide for Sen. Kirsten Gillibrand, D-N.Y., until a month ago, has entered the Democratic primary to challenge Republican Rep. John Katko in New York’s competitive 24th District.

On Thursday, Deacon filed her paperwork with the Federal Election Commission — joining Syracuse University Professor Eric Kingson who launched his own campaign this summer for the party's nomination. “I have seen — up close and personal — how the issues in front of Congress affect real people’s lives, and I want to be a real voice for Central New York,” Deacon said in a statement posted on her website.

Deacon's candidacy in what could be a large Democratic field was encouraged by Gillibrand, a Democrat with knowledge of the 24th District said. Deacon had worked as Gillibrand’s regional director in Syracuse since she was appointed in 2009. Lauren Passalacqua, a spokeswoman for Gillibrand, said Deacon left the job last month.

New York’s 24th District is rated a Tossup by the Rothenberg & Gonzales Political Report /Roll Call. The district, which President Barack Obama won by 57 percent in 2012, has swung back and forth during the past four elections — sending Democrats to Congress in presidential cycles such as this one, Republicans in mid-terms like the last.

Katko, who ousted Democratic Rep. Dan Maffei in 2014, is one of 15 Democrats listed on the DCCC’s list of “One-Term Wonders ," and is in the National Republican Congressional Committee's "Patriot Program," which was designed to protect vulnerable members.

“The DCCC had several meetings and conversations with Colleen Deacon previous to her announcement, in addition to other potential candidates," a DCCC aide said on Thursday of the group's involvement in the primary.

Last week, the NRSC released polling showing Katko with a lead over Kingson. A spokesman for the group declined to comment for this story.